Instrument panel-air conditioning duct assembly for vehicle

ABSTRACT

An instrument panel ( 2 ) includes a surface-side molded panel member ( 3 ) made of a synthetic resin and a back-side molded panel member ( 4 ) made of a synthetic resin. The back-side molded panel member ( 4 ) is vibration-welded to the surface-side molded panel member ( 3 ) through a plurality of projections ( 5 ) existing on its surface opposed to the surface-side molded panel member ( 3 ), and a heat-insulating gap ( 6 ) is left between both of the molded panel members ( 3, 4 ). An air-conditioning duct ( 10 ) is formed using a portion ( 22 ) of the back-side molded panel member ( 4 ) as a portion of its peripheral wall. Thus, it is possible to provide an instrument panel-air conditioning duct assembly ( 1 ) for a vehicle, which is produced at a reduced number of steps.

FIELD OF THE INVENTION

The present invention relates to an instrument panel-air conditioningduct assembly for a vehicle.

BACKGROUND ART

There is such a conventional known assembly in which an instrument panelmade of a synthetic resin and an air-conditioning duct made of asynthetic resin are vibration-welded to each other. In this case, theinstrument panel is comprised of a back-side molded panel member formedby an injection molding, and a skin affixed to a surface of theback-side molded panel member through an adhesive. The air-conditioningduct is formed by a blow molding, so that it has a plurality ofbranched-off duct portions, and pinched-off portions connected to theduct portions are used as portions to be welded.

However, the conventional instrument panel suffers from the followingproblems: An operation for applying an adhesive to the back-side moldedpanel member and a foam-molding operation for affixing the skin arerequisite, and time for curing the adhesive is also required, resultingin an increased number of steps for producing the instrument panel andthus the assembly.

In the back-side molded panel member, the following problem also isencountered: If a thickened portion such as a member-mounting protrusionis formed on a back of the back-side molded panel member, a sink markcorresponding to the thickened portion, namely, a recess is formed on asurface of the back-side molded panel member, and the skin is conformedto the recess. For this reason, the uniformity of the surface of theinstrument panel is reduced, resulting in a reduction in commercialvalue of the assembly.

A further problem encountered in the conventional assembly is that theweight of the assembly is increased as a result of the air-conditioningduct including the portions to be welded, which are extra from theviewpoint of its intrinsic function.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide an instrumentpanel-air conditioning duct assembly of the above-described type,wherein the number of producing steps is reduced, and the uniformity ofthe surface of the instrument panel and moreover, a reduction in weightis achieved.

To achieve the above object, according to the present invention, thereis provided an instrument panel-air conditioning duct assemblycomprising an instrument panel which includes a surface-side moldedpanel member made of a synthetic resin and a back-side molded panelmember made of a synthetic resin, the back-side molded panel memberbeing vibration-welded to the surface-side molded panel member through aplurality of projections existing on a surface thereof opposed to thesurface-side molded panel member with a heat-insulating gap left betweenboth of the molded panel members; an air-conditioning duct being formedusing a portion of the back-side molded panel member as a portion of aperipheral wall thereof.

The instrument panel is comprised of the surface-side molded panelmember and the back-side molded panel member vibration-welded to eachother and, hence, it is possible to reduce the number of steps forproducing the instrument panel and in turn the number of steps forproducing the assembly.

Even if the back-side molded panel member is provided with a thickenedportion which produces a sink mark on the surface of the back-sidemolded panel member, an influence of the sink mark cannot appear on thesurface-side molded panel member, because the back-side molded panelmember is spaced apart from the surface-side molded panel member, andthus, the uniformity of the surface of the instrument panel is ensured.

Further, a portion of the peripheral wall of the air-conditioning ductis a portion of the back-side molded panel member, and theair-conditioning duct need only have a pipe-shaped form required tofulfill its intrinsic function. Therefore, it is possible to achieve areduction in weight of the duct and thus a reduction in weight of theassembly.

When cold air is allowed to flow into the duct during cooling, a portionof the back-side molded panel member and a portion in the vicinitythereof are cooled by the cold air, but the transmission of the coolingto the surface-side molded panel member is inhibited by theheat-insulating gap. Therefore, dew condensation cannot be produced onthe surface-side molded panel member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of an instrument panel-air conditioningduct assembly;

FIG. 2 is an enlarged sectional view taken along a line 2—2 in FIG. 1;

FIG. 3 is an enlarged view of a portion of the instrument panel asindicated in FIG. 2;

FIG. 4 is an enlarged view of another portion of the instrument panel asindicated in FIG. 2; and

FIG. 5 is an enlarged view of yet another portion of the instrumentpanel as indicated in FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

In an instrument panel-air conditioning duct assembly 1 for a vehicleshown in FIGS. 1 and 2, an instrument panel 2 includes a surface-sidemolded panel member 3 made of a synthetic resin, and a back-side moldedpanel member 4 made of a synthetic resin extending over thesubstantially entire back of the panel member 3. The back-side moldedpanel member 4 is vibration-welded to the surface-side molded panelmember 3 through a plurality of projections existing on its side opposedto the surface-side molded panel member 3, namely, on its surface, e.g.,projecting stripes 5 extending in a lateral direction of the vehicle inthe embodiment, and a heat-insulating gap 6 exists between both of themolded panel members 3 and 4.

The surface-side molded panel member 3 is formed in a vacuum moldingmanner using a sheet having a single-layer structure or a sheet havingtwo or more layers, e.g., a sheet having a three-layer structure in theembodiment. The surface-side molded panel member 3 is comprised of abase layer 7 made of PP (polypropylene), a cushion layer 8 integral withthe base layer 7 and made of a PP foam, and a surface layer 9 integralwith the cushion layer 8 and made of TPO (a thermoplastic olefin). Thebase layer 7 is vibration-welded to the back-side molded panel member 4.

The back-side molded panel member 4 is of a single-layer structure andis formed in an injection molding manner using PP. This panel member 4is a strength member for the instrument panel 2 and hence, its thicknessis set at a value exceeding the thickness of the base layer 7 of thesurface-side molded panel member 3. The thickness of the base layer 7 isset at a minimum value which does not impede, for example, the vibrationwelding interference from the demand for a reduction in weight of theassembly 1.

Because the instrument panel 2 comprises the surface-side molded panelmember 3 and the back-side molded panel member 4 vibration-welded toeach other, as described above, the number of steps for producing theinstrument panel 2 and thus the number of steps for producing theassembly 1 can be reduced.

An air-conditioning duct 10 includes a first duct member 11 and a secondduct member 12 which communicates with the first duct member 11. Thefirst duct member 11 extends in the lateral direction of the vehicle ata substantially central portion of the instrument panel 2 in alongitudinal direction of the vehicle. On the other hand, the secondduct member 12 extends in the lateral direction of the vehicle along anair blow-off port 13 for a defroster exiting in a front portion of theinstrument panel 2 in the longitudinal direction of the vehicle. The airblow-off port 13 comprises bore portions 14 and 15 defined in thesurface-side and back-side molded panel members 3 and 4, with edges ofthe bores 14 and 15 being in close contact with each other.

In order to form the first duct member 11, the back-side molded panelmember 4 has, at a substantially central portion of its back in thelongitudinal direction of the vehicle, a pair of plate-shaped mountingportions 16 protruding in an opposed relation to each other with apredetermined gap left therebetween. On the other hand, the first ductmember 11 has a tub-shaped duct body 17 made of a synthetic resin, whoseopposed sidewalls 18 are mounted to the mounting portions 16,respectively. In the embodiment, engagement claws 19 each folded fromeach of end edges of the sidewalls 18 to form an acute angle with eachof an outer surface of each sidewall 18 are engaged into engagementbores 20 in the mounting portions 16 from inside the mounting portions16. The engagement claws 19 are inserted between the mounting portions16 in such a manner that the distance between both of the sidewalls 18is reduced forcibly and hence, the engagement of the engagement claws 19and the engagement bores 20 is maintained by restoring forces of thesidewalls 18.

Seal members 21 are mounted between upper inner surfaces of theengagement bores 20 and outer surfaces of the engagement claws 19opposed to the bores 20, respectively, whereby the leakage of cold airand warm air to the outside through the bores 20 is prevented.

In this way, the first duct member 11 is formed using, as a portion ofits peripheral wall, a portion 22 of the back-side molded panel member4, namely, the mounting portions 16 and a portion 23 sandwiched betweenthe mounting portions 16.

As is also shown in FIG. 3, flat portions of the back-side molded panelmember 4 existing between on opposite sides of the bore 15 of theair-blow-off port are used as mounting portions 24 to form the secondduct member 12. On the other hand, the second duct member 12 has atub-shaped duct body 25 made of a synthetic resin, whose opposedsidewalls 26 are mounted to the mounting portions 24, respectively. Inthe embodiment, engagement portions 27 are connected to the end edges ofthe sidewalls 18, respectively. In each of the engagement portions 27, aflat portion 28 folded outwards at a substantially right angle from eachof end edges of the sidewalls 26 is opposed to a back of each of themounting portions 24. A first engagement portion 29 rising from an outeredge of each of the flat portions 28 is engaged with an outer innersurface of an engagement bore 30 in the mounting portion 24, and asecond engagement portion 31 folded to extend outwards from the firstengagement portion 29 and substantially in parallel to the flat portion28 is engaged with an edge of the engagement bore 30 on the side of thesurface of each of the mounting portions 24. Both of the secondengagement portions 31 are passed through the engagement bores 30 insuch a manner that the distance between both of the sidewalls 26 isforcibly reduced. Therefore, the engagement of the first and secondengagement portions 29 and 31 and the engagement bores 30 as well astheir edges is maintained by restoring forces of thee sidewalls 26.

Seal members 21 are mounted between the backs of the mounting portions24 and upper surfaces of the flat portions 28 opposed to the backs ofthe mounting portions 24, respectively, thereby preventing the leakageof cold air and warm air to the outside through gaps between themounting portions 24 and the flat portions 28.

In this way, the second duct member 12 is formed using, as a portion ofits peripheral wall, a portion 22 of the back-side molded panel member4, namely, a portion having the bore portion 15 of the air blow-offport. Each of the tub-shaped duct bodies 17 and 25 is formed in aninjection molding process using PP, for example.

As described above, a portion of the peripheral wall of theair-conditioning duct 10 is the portion 22 of the back-side molded panelmember 4, and the duct 10 need only have a pipe-shaped form required tofulfill its intrinsic function. Therefore, it is possible to achieve areduction in weight of the duct 10 and thus a reduction in weight of theassembly 1.

When cold air is allowed to flow into the air-conditioning duct 10during cooling, the portion 22 of the back-side molded panel member 4and a portion in the vicinity thereof are cooled by the cold air, butthe transmission of the cooling to the surface-side molded panel member3 is inhibited by the heat-insulating gap 6. Therefore, dew condensationcannot be produced on the surface-side molded panel member 3.

The back-side molded panel member 4 can also function as a supportmember for various members, and for example, a wire harness mountingportion 32, a meter inner panel mounting portion 33 and the like areprojectingly provided on the back of the panel member 4. Even if theback-side molded panel member 4 is provided with the thickened portionswhich produce a sink mark on the surface thereof, an influence of thesink mark cannot appear on the surface-side molded panel member 3,because the back-side molded panel member 4 is spaced apart from thesurface-side molded panel member 3, whereby the uniformity of thesurface of the instrument panel 2 is ensured.

In the assembly 1, the surface-side and back-side molded panel members 3and 4 as well as the tub-shaped duct bodies 17 and 25 can be formedusing the same material, and the coupling of the panel members 3 and 4to each other and the assembling of the duct bodies 17 and 25 to theback-side molded panel member 4 can be-achieved without use of afastening plate such as a machine screw. The recyclability of theassembly 1 of this type can be enhanced.

On the other hand, the tub-shaped duct bodies 17 and 25 are notvibration-welded to the back-side molded panel member 4 and hence, thesynthetic resin forming the duct bodies 17 and 25 need not be the sameas that forming the back-side molded panel member 4. Therefore, the costof production of the assembly 1 can be reduced by using a syntheticresin different from and less expensive than that forming the back-sidemolded panel member 4, or by using a regenerated synthetic resin as thesynthetic resin for the duct bodies 17 and 25. Even in this case, theseparability of the duct bodies 17 and 25 from the back-side moldedpanel member 4 can be improved and hence, the recyclability of the ductbodies 17 and 25 cannot be detracted.

1. An instrument panel-air conditioning duct assembly for a vehiclecomprising: an instrument panel which includes a surface-side moldedpanel member made of a synthetic resin and a back-side molded panelmember made of a synthetic resin, said back-side molded panel memberbeing vibration-welded to said surface-side molded panel member througha plurality of projections existing on a surface thereof opposed to saidsurface-side molded panel member with an insulating gap left betweensaid molded panel members; and an air-conditioning duct supported bysaid back-side molded panel member, said air-conditioning duct formed byattaching a duct member to said back-side molded panel member such thata portion of said back-side molded panel member forms a wall of saidduct.
 2. An instrument panel-air conditioning duct assembly for avehicle according to claim 1, wherein said air-conditioning duct has atub-shaped duct body whose opposed sidewalls are mounted to saidback-side molded panel member.
 3. An instrument panel-air conditioningduct assembly for a vehicle according to claim 2, wherein saidtub-shaped duct body is formed of a synthetic resin selected from thegroup consisting of a synthetic resin different from the synthetic resinforming the back-side molded panel member and a regenerated syntheticresin.
 4. An instrument panel-air conditioning duct assembly for avehicle according to claim 2, further comprising hook-shaped elements onsaid opposed side walls of said tub-shaped duct body for engagingcorresponding apertures in said back-side molded panel member.
 5. Aninstrument panel-air conditioning duct assembly for a vehicle accordingto claim 4, wherein said tub-shaped duct body is sufficiently flexibleto allow said opposed side walls thereof to be bent inward, each towardthe other.
 6. An instrument panel-air conditioning duct assembly for avehicle according to claim 4, further comprising seal members forfilling free space in said apertures existing after insertion of saidhook-shaped elements, said seal members preventing leakage of air fromsaid air-conditioning duct.
 7. An instrument panel-air conditioning ductassembly for a vehicle according to claim 1, wherein mounting portionsprotrude from a rear surface of said back-side molded panel member andsaid duct member is attached to said mounting portions.
 8. An instrumentpanel-air conditioning duct assembly for a vehicle according to claim 4,wherein mounting portions protrude from a rear surface of said back-sidemolded panel member and said apertures are provided in said mountingportions.
 9. An instrument panel-air conditioning duct assembly for avehicle comprising: an instrument panel including a surface-side moldedpanel member having an outer surface visible to occupants of saidvehicle, and a back-side molded panel member, each panel member made ofa synthetic resin, said back-side molded panel member having mountingmeans located on a back surface for attaching said instrument panel tosaid vehicle and being vibration-welded to said surface-side moldedpanel member via a plurality of projections extending from a frontsurface thereof that is opposed to said surface-side molded panelmember; an insulating gap residing between said molded panel membersafter said panel members have been vibration-welded; and anair-conditioning duct formed by connecting a duct body to a matingportion of said back-side molded panel member, such that a portion ofsaid back-side molded panel member forms a wall of said duct; whereinconstructing said instrument panel in such a manner prevents defectscommonly visible on said front surface of said back-side molded panelmember as a result of molding said mounting means from being transferredto said outer surface of said surface-side molded panel member; andwherein said insulating gap substantially prevents the temperature ofair flowing through said air conditioning duct from affecting thetemperature of said surface-side molded panel member.
 10. An instrumentpanel-air conditioning duct assembly for a vehicle according to claim 9,wherein said duct body is tub-shaped and has opposed sidewalls that aremounted to said back-side molded panel member.
 11. An instrumentpanel-air conditioning duct assembly for a vehicle according to claim10, wherein said tub-shaped duct body is formed of a synthetic resinselected from the group consisting of a synthetic resin different fromthe synthetic resin forming the back-side molded panel member, and aregenerated synthetic resin.
 12. An instrument panel-air conditioningduct assembly for a vehicle according to claim 10, further comprisinghook-shaped elements on said opposed side walls of said tub-shaped ductbody for engaging corresponding apertures in said back-side molded panelmember.
 13. An instrument panel-air conditioning duct assembly for avehicle according to claim 12, wherein said tub-shaped duct body issufficiently flexible to allow said opposed side walls thereof to bebent inward, each toward the other.
 14. An instrument panel-airconditioning duct assembly for a vehicle according to claim 12, furthercomprising seal members for filling free space in said aperturesexisting after insertion of said hook-shaped elements, said seal memberspreventing leakage of air from said air-conditioning duct.
 15. Aninstrument panel-air conditioning duct assembly for a vehiclecomprising: an instrument panel, said instrument panel furthercomprising: a surface-side molded panel member made of a syntheticresin; a back-side molded panel member made of a synthetic resin, saidback-side molded panel member having a mounting portion extendingoutward from a back surface thereof for receiving a portion of a ductbody and being vibration-welded to said surface-side molded panel membervia a plurality of projections extending from a front surface thereofthat is opposed to said surface-side molded panel member, and a gapresiding between said molded panel members after said panel members havebeen vibration-welded; and an air-conditioning duct supported by saidback-side molded panel member, said air-conditioning duct formed byremovably attaching a tub-shaped flexible duct body to said mountingportion on said back-side molded panel member such that a portion ofsaid back-side molded panel member forms a wall of said duct; whereinsaid flexible duct body is retained on said back-side molded panelmember by the engagement of hook-shaped elements extending from opposedside walls of said tub-shaped flexible duct body with correspondingapertures in said mounting portion of said back-side molded panelmember.
 16. An instrument panel-air conditioning duct assembly for avehicle according to claim 15, wherein said flexible duct body is formedof a synthetic resin selected from the group consisting of a syntheticresin different from the synthetic resin forming the back-side moldedpanel member, and a regenerated synthetic resin.
 17. An instrumentpanel-air conditioning duct assembly for a vehicle according to claim15, further comprising seal members for filling free space in saidapertures existing after insertion of said hook-shaped elements, saidseal members preventing leakage of air from said air-conditioning duct.18. An instrument panel-air conditioning duct assembly for a vehicleaccording to claim 15, wherein said tub-shaped flexible duct body isfurther retained on said back-side molded panel member by restorativeforces in said opposed side walls of said flexible duct body pushingagainst said mounting portion of said back-side molded panel member. 19.An instrument panel-air conditioning duct assembly for a vehicleaccording to claim 15, wherein constructing said instrument panel insuch a manner prevents defects commonly visible on said front surface ofsaid back-side molded panel member as a result of molding mounting meanstherein from being transferred to said surface-side molded panel member.20. An instrument panel-air conditioning duct assembly for a vehicleaccording to claim 15, wherein said gap substantially prevents thetemperature of air flowing through said air conditioning duct fromaffecting the temperature of said surface-side molded panel member.